Barbiturates inhibit hexose transport in cultured mammalian cells and human erythrocytes and interact directly with purified GLUT-1.
Barbiturates inhibit hexose transport in cultured mammalian cells and human erythrocytes and interact directly with purified GLUT-1.
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巴比妥类药物抑制培养的哺乳动物细胞和人红细胞中的己糖转运，并直接与纯化的 GLUT-1 相互作用。
DOI：
10.1021/bi00002a019
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发表时间：
1995
期刊：
影响因子：
2.9
通讯作者：
Haspel,HC
中科院分区：
文献类型：
--
作者：
Honkanen,RA;McBath,H;Kushmerick,C;Callender,GE;Scarlata,SF;Fenstermacher,JD;Haspel,HC
1994年11月7日收到的修订版Mandarin pt ®摘要：巴比妥类药物减少脑血流量、代谢和葡萄糖穿过血脑屏障的转移。本文研究了巴比妥类药物对培养的哺乳动物细胞系和人红细胞己糖转运的影响。在10和0.5 mM浓度下，戊巴比妥分别抑制3 T3-C2鼠成纤维细胞中[3 H]-2-dGlc摄取约95%和约50%。在存在或不存在戊巴比妥的情况下，[3 H]-2-dGlc的摄取与时间呈线性关系，并且抑制百分比恒定。这表明己糖转运，而不是磷酸化，被巴比妥酸盐抑制。戊巴比妥对3 T3-C2细胞中己糖转运的抑制是快速的（< 1分钟），不容易逆转，不因白蛋白[1%（w/v）]的存在而改变，并且不依赖于温度（4-37 ℃）和细胞表面GLUT-1的水平。戊巴比妥、硫代丁巴比妥和巴比妥抑制己糖转运蛋白3 T3-C2细胞的IC 50分别为0.8、1.0和4 mM。这与Meyer-Overton规则和巴比妥类药物的药理学一致。氟烷（< 10 mM）和乙醇[< 0.4%（v/v）]均不显著抑制己糖转运。抑制3 T3-C2细胞摄取[3 H]-2-dGlc的戊巴比妥（0.5 mM）可降低表观Vmax（~ 50%），但不改变表观Km（~ 0.5 mM）。在人红细胞和其他四种培养的哺乳动物细胞系中也观察到巴比妥酸盐对己糖转运的抑制作用，而乙醇[< 0.4%（v/v）]对己糖转运无抑制作用。戊巴比妥淬灭（Qmax~ 75%）纯化和重构GLUT-1~ 3 mM的固有荧光。淬灭是独立的葡萄糖占用，是不变的温和的蛋白水解失活，并没有出现直接涉及脂质双层的扰动。我们提出巴比妥类药物可以直接与GLUT-1相互作用，抑制载体的内在活性。Glc主要通过脑毛细血管内皮细胞的GLUT-1穿过血脑屏障。巴比妥类药物部分抑制这一过程可能具有脑保护作用。
Revised Manuscript Received November 7, 1994® abstract: Barbiturates reduce cerebral blood flow, metabolism, and Glc transfer across the blood—brain barrier. The effect of barbiturates on hexose transportin cultured mammalian cell lines and human erythrocytes was studied. Pentobarbitalinhibits [3H]-2-dGlc uptake in 3T3-C2 murine fibroblasts by~ 95% and~ 50% at 10 and 0.5 mM, respectively. Uptake of [3H]-2-dGlc is linear with time in the presence or absence of pentobarbital, and the percent inhibition is constant. This suggests that hexose transport, not phosphorylation, is inhibited by barbiturates. Inhibition bypentobarbital of hexose transport in 3T3-C2 cells is rapid (< 1 min), is not readily reversible, is not altered by thepresence of albumin [1%(w/v)], and is independent of temperature (4—37 C) and the level of cell surface GLUT-1. The ICso’s for inhibition of hexose transportin 3T3-C2 cells by pentobarbital, thiobutabarbital, and barbital are 0.8, 1.0, and 4 mM, respectively. This is consistent with both the Meyer-Overton rule and the pharmacology of barbiturates. Neither halothane (< 10 mM) nor ethanol [< 0.4%(v/v)] significantly inhibits hexose transport. Inhibition bypentobarbital (0.5 mM) of [3H]-2-dGlc uptake by 3T3-C2 cells decreases the apparent Vmax (~ 50%) but does not alter the apparent Km (~ 0.5 mM). Inhibition of hexose transport by barbiturates, but not ethanol [< 0.4%(v/v)], is also observed in human erythrocytes and four other cultured mammalian cell lines. Pentobarbital quenches (Qmax~ 75%) the intrinsic fluorescence of purified and reconstituted GLUT-1~ 3 mM). Quenching is independent of Glc occupancy, is unchanged by mild proteolytic inactivation, and does not appear to directly involve perturbations of the lipid bilayer. We propose that barbiturates can interact directly with GLUT-1 and inhibit the intrinsic activity of the carrier. Glc crosses the blood—brain barrier primarily via the GLUT-1 of the endothelial cells of cerebral capillaries. Partial inhibitionof this process by barbiturates may be of significance to cerebral protection.